So, you bought Grandpa an iPad. You thought he could do things like keep track of his doctor’s appointments and watch World War II documentaries on Netflix. Instead he uses it primarily as a $500 coaster for his morning coffee.

Welcome to the world of tech buyer’s remorse. There are plenty of reasons this year’s hottest gadgets turn out to be duds on Christmas morning. Maybe the technology was just too advanced for the 95-year-old or the 3-year-old it was bought for. Maybe the gadget was the wrong model, broken or just plain boring.

In the end, you’re going to have to do what every red-blooded American shopper fears most: enduring a long return line full of disgruntled customers. Just in case you were thinking of waiting a few months to beat the holiday crowds, forget it, because the time window for returning tech gifts is usually pretty short when compared with other products.

At Best Buy, you have just 14 days to return any unwanted computers, monitors, projectors, camcorders, digital cameras or tablets, compared with the usual 30 days. Walmart gives you 15 days for tech gear, 75 days less than the usual return policy allows. Remember, that’s the time after purchase, so if somebody did their Christmas shopping early, you might be out of luck.

You’re a little bit better off if you ordered through Amazon. The site gives you 30 days after a computer or Kindle is delivered to return it for a gift certificate or refund.

If it all seems like a hassle to you, you’re not alone. According to a poll by the National Retail Federation, only 35% of Americans returned one or more gifts after last year’s holiday season. Either everyone was happy with what they got, or a lot of people decided that returning the iPod Shuffle they received for the iPod Touch they wanted wasn’t worth getting off the couch.

If you got something you don’t want, don’t worry about hurting anybody’s feelings when returning it — a full 61.9% of shoppers said that they included gift receipts with their gifts last year, the highest rate since the poll was first conducted.

What happens if after one month Gramps decides an iPad just isn’t for him or your picky 7-year-old rejects his LeapPad for the box it came in?

Luckily there are still a ton of people out there who want your high-tech swag. The black 64-GB, wi-fi- and 3G-equipped iPad 2 is selling mostly in the $700-$800 price range on eBay, not a huge drop-off from its original $829 sticker price. Move fast, though; the closer it gets to the release date of a new product, the less your old version will sell for online.

If you’re feeling the holiday spirit, you might even want to donate your computer or iPad to charity. Computers with Causes will match your unwanted desktop, laptop or iPad with someone in need, while the Hollyrod Foundation is often looking for iPads to help kids with autism. Recycling for Charities will either refurbish your nonworking electronics for charity or dispose of them in an environmentally safe way.

If none of those options seem appealing, there is always the ancient art of regifting. Just because you don’t want your BlackBerry PlayBook, it doesn’t mean your Aunt Edna won’t be able to find a use for it, even it’s just as a coaster.